Evacuator system having multi-port evacuator

ABSTRACT

A pneumatically actuated vacuum pump is disclosed. The pneumatically actuated vacuum pump includes a body. The body defines at least two converging motive sections each having an outlet end, at least two diverging discharge sections each having an inlet end, and at least one Venturi gap. The Venturi gap is located between the outlet ends of the at least two converging motive sections and the inlet ends of the at least two diverging discharge sections.

TECHNICAL FIELD

This application relates to an operating system generating vacuum usingan evacuator, and in particular to an evacuator including multiplemotive and discharge ports that provides different characteristics ofsuction vacuum and suction flow rates.

BACKGROUND

In some vehicles, vacuum is used to operate or assist in the operationof various devices. For example, vacuum may be used to assist a driverapplying vehicle brakes, turbocharger operation, fuel vapor purging,heating and ventilation system actuation, and driveline componentactuation. If the vehicle does not produce vacuum naturally, such asfrom the intake manifold, then a separate vacuum source is required tooperate such devices. For example, in some boosted engines where intakemanifold pressures are often at pressures greater than atmosphericpressure, intake manifold vacuum may be replaced or augmented withvacuum from an evacuator.

As used herein, an evacuator is defined as a converging, divergingnozzle assembly with three connections, a motive port, a discharge port,and a suction port connected to a device requiring vacuum. The evacuatormay be an ejector or an aspirator, depending on the pressures at themotive and discharge ports. Specifically, if the pressure at the motiveport of the evacuator is at atmospheric pressure and if the dischargeport is less than atmospheric pressure, then the evacuator may operateas an aspirator. If the pressure at the motive port of the evacuator isgreater than atmospheric pressure and the discharge port of theevacuator is less than the pressure at the motive port but at leastatmospheric pressure, then the evacuator operates as an ejector. A lowpressure region may be created within the evacuator so that air can bedrawn from a vacuum reservoir or may directly act on a device requiringvacuum, thereby reducing pressure within the vacuum reservoir or devicerequiring vacuum.

Those skilled in the art readily understand that the various vacuumconsuming devices in a vehicle typically include different requirementsfor suction vacuum as well as suction flow rate. For example, a fuelvapor purge canister produces a continuous flow requiring a relativelylow level of vacuum over a longer period of time when compared to abrake boost canister. However, the brake boost canister typicallyrequires relatively higher suction vacuum when compared to the fuelvapor purge canister. Moreover, a crankcase ventilation system needs tobe purged continuously, and therefore requires a constant supply ofvacuum. In contrast, the fuel vapor purge canister may only need purgingfor a specified period of time after starting of the vehicle.

Some existing vehicles may supply vacuum to each of the devicesrequiring vacuum (i.e., the brake boost canister, fuel vapor purgecanister, etc.) separately. This current approach for providing vacuumresults in an increased number of parts, complexity, and cost to thevehicle. Thus, there is a continuing need in the art for an improved,low-cost approach for providing both high suction vacuum and highsuction flow rate to multiple vacuum consuming devices within a vehicle.

SUMMARY

In one embodiment, a pneumatically actuated vacuum pump is disclosed.The pneumatically actuated vacuum pump includes a body. The body definesat least two converging motive sections each having an outlet end, atleast two diverging discharge sections each having an inlet end, and atleast one Venturi gap. The Venturi gap is located between the outletends of the at least two converging motive sections and the inlet endsof the at least two diverging discharge sections.

In another embodiment, a turbocharged engine air system is disclosed.The turbocharged engine air system includes at least two devicesrequiring vacuum, a turbocharger having a compressor fluidly connectedto an intake manifold of an engine, and an evacuator. The evacuatordefines at least two motive sections, at least two discharge sections,and at least two suction ports. The at least two discharge sections ofthe evacuator are fluidly connected to the intake manifold of the engineat a location downstream of the compressor, and each of the at least twosuction ports of the evacuator are fluidly connected to one of the atleast two devices requiring vacuum.

In yet another embodiment, a normally aspirated engine air systemincluding an engine and a throttle located upstream of an intakemanifold of the engine is disclosed. The system includes at least twodevices requiring vacuum and an evacuator. The evacuator defines atleast two motive sections, at least two discharge sections, and at leasttwo suction ports. The at least two discharge sections are fluidlyconnected to the intake manifold of the engine at a location downstreamof the throttle, and each of the at least two suction ports are fluidlyconnected to one of the at least two devices requiring vacuum.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram including flow paths and flow directionsof one embodiment of an internal combustion engine turbo systemincluding an evacuator.

FIG. 2 is a schematic diagram of the evacuator shown in FIG. 1.

FIG. 3 is a perspective view of the evacuator in FIG. 2.

FIG. 4 is an exploded view of the evacuator shown in FIG. 3.

FIG. 5 is an exploded view of the evacuator shown in FIG. 2, taken alongsection line B-B in FIG. 4.

FIG. 6 is an enlarged view of a portion of the evacuator shown in FIG.3, taken along section line B-B in FIG. 4.

FIG. 7 is an end view of the evacuator when viewed from the dischargeport.

FIG. 8 is a longitudinal cross-sectional view of another embodiment ofan evacuator.

FIG. 9 is an exploded, longitudinal cross-sectional view of oneembodiment of an evacuator.

FIG. 10 is an illustration of a check valve element for use in theevacuator shown in FIG. 9.

FIG. 11 is a schematic diagram including flow paths and flow directionsof another embodiment of an internal combustion engine turbo systemincluding a multi-port evacuator.

FIG. 12 is an elevated view of the evacuator shown in FIG. 11.

FIG. 13 is a cross-sectioned view of the evacuator taken along sectionline C-C in FIG. 12.

FIG. 14 is an alternative embodiment of the evacuator shown in FIG. 12.

FIG. 15 a schematic diagram including flow paths and flow directions ofa normally aspirated internal combustion engine system including theevacuator shown in any of FIG. 11 or 14.

DETAILED DESCRIPTION

The following detailed description will illustrate the generalprinciples of the invention, examples of which are additionallyillustrated in the accompanying drawings. In the drawings, likereference numbers indicate identical or functionally similar elements.As used herein, the term fluid may include any liquid, suspension,colloid, gas, plasma, or combinations thereof.

Referring now to FIG. 1, an exemplary turbocharged engine air system 10for providing vacuum to a vehicle vacuum system is disclosed. The engineair system 10 may include an internal combustion engine 12, an aircleaner 14, an evacuator 20, a compressor 24, a turbine 26, a throttle28, a vacuum reservoir or canister 30, and a vacuum consuming device 32.The internal combustion engine 12 may be, for example, a spark ignited(SI) engine or a compression ignition (CI) engine. In one embodiment,the internal combustion engine 12 may be included in an electricmotor/battery system that is part of a hybrid vehicle. In the embodimentas shown in FIG. 1, the internal combustion engine 12 is boosted. Thismeans that the compressor 24 and turbine 26 may be part of aturbocharger for improving the power output and overall efficiency ofthe internal combustion engine 12. The turbine 26 may include a turbinewheel (not illustrated in FIG. 1) that harnesses and converts exhaustenergy into mechanical work through a common shaft 40 to turn acompressor wheel (not illustrated in FIG. 1) of the compressor 24. Thecompressor wheel ingests, compresses, and feeds air at elevatedoperating pressures into the intake manifold 42 of the internalcombustion engine 12.

The vacuum canister 30 may be supplied vacuum from the evacuator 20. Theevacuator 20 is supplied air from the compressor 24. Specifically, cleanair at atmospheric pressure exits the air cleaner 14 and may becompressed by the compressor 24 before passing through the evacuator 20.As explained in greater detail below, the evacuator 20 may be used tosupply vacuum to the vacuum canister 30. In particular, the amount ofvacuum supplied by the evacuator 20 may be adjusted based on thespecific operating conditions of the engine air system 10, which isexplained in greater detail below.

The throttle 28 may be located downstream of the air cleaner 14 and thecompressor 24, and upstream of an intake manifold 42 of the internalcombustion engine 12. The throttle 28 may be opened as an operatordepresses upon an accelerator pedal (not shown). When the throttle 28 isopened, compressed air from the compressor 24 is free to fill the intakemanifold 42 of the internal combustion engine 12, thereby increasing thepressure at the intake manifold 42. Those skilled in the art willappreciate that the throttle 28 may be positioned in a plurality ofpartially opened positions based on the amount of depression of theaccelerator (not shown). Since the engine air system 10 is turbocharged,the pressure at the intake manifold 42 may increase to a pressure thatis above atmosphere as the throttle 28 is opened.

The evacuator 20 may include a first engine air connection 44, a secondengine air connection 46, and a pneumatically actuated vacuum pump 50that is shown in FIG. 2. The engine air connection 44 of the evacuator20 may be fluidly connected to the engine air system 10 at a locationupstream of the throttle 28 and downstream of the compressor 24. Theengine air connection 46 of the evacuator 20 may be fluidly connected tothe engine air system 10 at a location upstream of the intake manifold42 and downstream of the throttle 28. The pneumatically actuated vacuumpump 50 may be used to supply vacuum to the vacuum canister 30.Specifically, the amount of vacuum supplied by the pneumaticallyactuated vacuum pump 50 may be adjusted based on the specific operatingconditions of the engine air system 10, and is explained in greaterdetail below. Although the evacuator 20 is illustrated as supplyingvacuum to the vacuum canister 30, those skilled in the art willappreciate that in an alternative embodiment, the evacuator 20 maydirectly supply vacuum to the vacuum consuming device 32.

The vacuum consuming device 32 may be a device requiring vacuum, such asa brake booster. In an embodiment, the vacuum consuming device 32 mayalso include additional vacuum consumers as well such as, for example,turbocharger waste gate actuators, heating and ventilation actuators,driveline actuators (e.g., four wheel drive actuators), fuel vaporpurging systems, engine crankcase ventilation, and fuel system leaktesting systems.

FIG. 2 is a schematic diagram of one embodiment of the evacuator 20shown in FIG. 1, and illustrates the pneumatically actuated vacuum pump50. The pneumatically actuated vacuum pump 50 may act as either anaspirator or an ejector depending on the pressure at the intake manifold42. Specifically, an aspirator is an evacuator with its motive fixed atatmospheric pressure and its discharge at below atmospheric pressure. Anejector is an evacuator with its motive pressure at above atmosphericpressure, and its discharge fixed at atmospheric pressure.

Referring to FIGS. 1-2, as used herein, the pneumatically actuatedvacuum pump 50 may be a converging, diverging nozzle assembly with threeor more connections. The pneumatically actuated vacuum pump 50 mayinclude a motive port 70 fluidly connected to the engine air connection44, a discharge port 74 fluidly connected to the engine air connection46, and one or more suction ports 72 fluidly connected to the vacuumcanister 30 or to one or more devices requiring vacuum 32. When aplurality of suction ports 72 are present as shown in a first embodimentin FIG. 3 and in a second embodiment in FIG. 8 and a third embodiment inFIG. 9, the suction ports 72′ may be collectively connected to the samedevice requiring vacuum 32 or the same vacuum canister 30 or may beindividually connected to different devices requiring vacuum 32 a and 32b, including the vacuum canister 30 as one possible device requiringvacuum.

Specifically, the motive port 70 of the aspirator 50 may be fluidlyconnected to the engine air system 10 downstream of the compressor 24,and the discharge port 74 of the aspirator 50 may be fluidly connectedto the engine air system 10 upstream of the intake manifold 42. Thoseskilled in the art will readily appreciate that since the evacuator 20is connected to the engine air system 10 downstream of the compressor24, this usually eliminates the need for a check valve between thecompressor 24 and the motive port 70 of the pneumatically actuatedvacuum pump 50. This is because the pressure at the engine airconnection 44, which is upstream of the throttle 28, should always begreater than the pressure at the engine air connection 46, which isdownstream of the throttle 28.

FIG. 3 is a perspective view of the pneumatically actuated vacuum pump50, FIG. 4 is an exploded view of the pneumatically actuated vacuum pump50 shown in FIG. 3, and FIG. 5 is a sectioned view of the explodedpneumatically actuated vacuum pump 50 shown in FIG. 4. Referring toFIGS. 3-5, a body 78 of the pneumatically actuated vacuum pump 50 maydefine a passageway 80 (shown in FIG. 5) that extends along an axis A-A.In the embodiment as illustrated in FIG. 3-5, the body 78 of thepneumatically actuated vacuum pump 50 includes four ports that areconnectable to subsystems of the internal combustion engine 12 (FIG. 1).Specifically, the pneumatically actuated vacuum pump 50 may include themotive port 70, the discharge port 74, and two suction ports 72. In thenon-limiting embodiment as shown, the pneumatically actuated vacuum pump50 includes two suction ports 72, where one of the suction ports 72 islocated along a top portion 84 of the pneumatically actuated vacuum pump50 and the remaining suction port 72 is located along a bottom portion86 of the pneumatically actuated vacuum pump 50. However, it is to beunderstood that in another embodiment only one suction port 72 locatedalong either the top portion 84 or the bottom portion 86 of thepneumatically actuated vacuum pump 50 may be used as well. Or in anotherembodiment, as shown in FIG. 8, the two suctions ports 72′ may both bedisposed along a top portion 84′ of the pneumatically actuated vacuumpump 50′, as will be described in more detail below.

Referring to FIG. 5, the passageway 80 of the pneumatically actuatedvacuum pump 50 may include a first tapering portion 92 (also referred toas a motive cone) in a motive section 90 of the passageway 80. Thepassageway 80 may also include a second tapering portion 93 (alsoreferred to as a discharge cone) in a discharge section 95 of thepassageway 80. The first tapering portion 92 of the passageway 80 mayinclude an inlet end 94 and an outlet end 96. Similarly, the secondtapering portion 93 of the passageway 80 may also include an inlet end98 and an outlet end 100.

As seen in FIG. 5, the first tapering portion 92 of the pneumaticallyactuated vacuum pump 50 may be fluidly coupled to the second taperingportion 93 by a Venturi gap 102A. The Venturi gap 102A may be a fluidjunction that places the suction ports 72 in fluid communication withthe motive section 90 and the discharge section 95 of the pneumaticallyactuated vacuum pump 50. As best seen in FIG. 6, the Venturi gap 102Amay be the lineal distance L1 measured between the outlet end 96 of thefirst tapering portion 92 and the inlet end 98 of the second taperingportion 93. Based on identifying inlet end 98 of the discharge section95 as shown in the figures, the second, third, and fourth Venturi gaps102B, 102C, and 102D are all considered part of the discharge section95, in particular as part of the second tapering portion 93 divergingaway from the motive section 90. The outlet end 96 of the first taperingportion 92 of the pneumatically actuated vacuum pump 50 represents theinlet of the Venturi gap 102A. Similarly, the inlet end 98 of the secondtapering portion 93 of the pneumatically actuated vacuum pump 50represents the outlet of the Venturi gap 102A.

Turning back to FIG. 5, the inlet ends 94, 98 and the outlet ends 96,100 of the passageway 80 of the pneumatically actuated vacuum pump 50may include any type of profile, such as, but not limited to, a circularshape, an ellipse shape, or another polygonal form. Moreover, thegradually, continuously tapering inner diameter extending from inletends 94, 98 and the outlet ends 96, 100 of the passageway 80 may definea hyperboloid or a cone. Some exemplary configurations for the outletend 96 of the first tapering portion 92 and the inlet end 98 of thesecond tapering portion 93 are presented in FIGS. 4-6 of co-pending U.S.patent application Ser. No. 14/294,727, filed on Jun. 3, 2014, which isincorporated by reference herein in its entirety.

Referring again to FIGS. 3-5, the body 78 of the pneumatically actuatedvacuum pump 50 may define a housing 110. The housing 110 may surround ordefine a portion of the second tapering portion 93 of the pneumaticallyactuated vacuum pump 50, in particular it may define the Venturi gaps102A, 102B, 102C, 102D. In the embodiment as illustrated, the housing110 may include a generally rectangular profile, however the housing110, in particular its exterior appearance, is not limited to arectangular profile.

As illustrated in the FIGS. 4-6 and 8, a plurality of additional Venturigaps 102B, 102C, 102D are located downstream of Venturi gap 102A, withinthe housing 110. In the embodiments shown in the figures, thepneumatically actuated vacuum pump 50 includes a total of four Venturigaps. It is to be understood that these illustrations are merelyexemplary embodiments of the pneumatically actuated vacuum pump 50 andthat any number of Venturi gaps are possible. For a dual suction portembodiment such as in FIG. 8, at least two Venturi gaps 102A and 102Care required so that at least Venturi gap 102A can be in fluidcommunication with the first suction port 72′a and at least the otherVenturi gap 102B can be in fluid communication with the second suctionport 72′b. With respect to each suction port, a plurality of Venturigaps may be positioned for alignment and fluid communication with eachrespective suction port, again providing for three, four or more totalVenturi gaps. As shown in FIG. 8, Venturi gaps 102A and 102B are influid communication with the first suction port 72′a and Venturi gaps102C and 102D are in fluid communication with the second suction port72′b. In an embodiment with three or four suction ports (not shown),potentially two suction ports 72′a, 72′b on the top surface 130 ofhousing 110 as shown in FIG. 8 and one or two additional suction portson the bottom surface 132 of the housing 110, a minimum of three or fourVenturi gaps would present.

Each Venturi gap 102A, 102B, 102C, 102D may be a void located within thehousing 110. Specifically, Venturi gaps 102A, 102B, 102C, 102D may eachbe similar to an interior cross-section of the housing 110. For example,as seen in FIG. 5, the Venturi gap 102A may include a generallyrectangular profile that substantially corresponds with the interiorcross-section of the housing 110. The flow of motive air through thefirst tapering portion 92 of the pneumatically actuated vacuum pump 50may increase in speed, but creates low static pressure. This low staticpressure draws air from the suction ports 72, 72′a into the Venturi gap102A. The remaining gaps 102B, 102C, 102D located downstream of theVenturi gap 102A may also be used to further draw in air from one ormore suction ports. In FIGS. 3-5, the Venturi gaps 102B, 102C, and 102Ddraw in air from two suction ports 72 at the same time. In FIG. 8, theVenturi gap 102B is used to further draw in air from the first suctionport 72′a and Venturi gaps 102C and 102D draw in air from the secondsuction port 72′b. Likewise, in the embodiment of FIG. 9, evacuator 50″,the Venturi gaps 102A and 102B drawn in air only from a first suctionport 72′c as a first obstruction 202 prevents drawing in air from thesecond suction port 72′d and the Venturi gaps 102C and 102D drawn in aironly from the second suction port 72′d as a second obstruction 204prevents drawing air in from the first suction port 72′c.

Referring to FIGS. 4-5, the housing 110 may include a top surface 130and a bottom surface 132. An upper check valve element 134 and an uppersuction piece 136 may be positioned against the top surface 130, and alower check valve element 140 and a lower suction piece 142 may bepositioned against the bottom surface 132 when the pneumaticallyactuated vacuum pump 50 is assembled (shown in FIG. 3). Although boththe upper check valve element 134 and the lower check valve element 140are illustrated, it is to be understood in another embodiment thehousing 110 may only include either the upper check valve element 134 orthe lower check valve element 140. Specifically, the upper check valveelement 134 may be positioned between the upper suction piece 136 andthe top surface 130 of the housing 110, and the lower check valveelement 140 may be positioned between the lower suction piece 142 andthe bottom surface 132 of the housing 110. In one embodiment, the uppersuction piece 136 and the lower suction piece 142 may each include barbs150 for mating with a hose (not illustrated) that connects the suctionports 72 to the vacuum canister 30 (FIG. 1). For the embodiments inFIGS. 8 and 9, any pieces or parts that are the same or similar to thoseidentified and described for FIGS. 3-5 have been given the samereference number.

The upper check valve element 134 and the lower check valve element 140may be constructed of a relatively flexible material such as, forexample, an elastomer. The flexible material enables the upper checkvalve element 134 and the lower check valve element 140 to bend ordeform during operation of the pneumatically actuated vacuum pump 50.

Turning now to FIG. 4, the upper check valve element 134 may include afirst section 160 and the lower check valve element 140 may include afirst section 162. The first sections 160, 162 of the upper check valveelement 134 and the lower check valve element 140 are each substantiallyparallel with the axis A-A of the pneumatically actuated vacuum pump 50.A plurality of outwardly projecting fingers or tabs 166A, 166B, 166C,166D may extend outwardly and in a direction generally transverse withrespect to the first section 160 of the upper check valve element 134.Similarly, a plurality of outwardly projecting fingers or tabs 170A,170B, 170C, 170D extend in a direction generally transverse with respectto the first section 162 of the lower check valve element 140. Each ofthe plurality of tabs may extend from one side of the first section 160or from both sides of the first section, typically aligned opposite oneanother.

Each of the tabs 166A, 166B, 166C, 166D of the upper check valve element134 may correspond to and is fluidly connected to one of the Venturigaps 102A, 102B, 102C, 102D. Similarly, each of the tabs 170A, 170B,170C, 170D of the lower check valve element 140 may also correspond toand is fluidly connected to one of the Venturi gaps 102A, 102B, 102C,102D, if present. As seen in FIG. 4, a recess 174 may be located alongan upper surface 176 of the lower suction cap 142. The recess 174 mayinclude a profile that generally corresponds with the lower check valveelement 140. Thus, the lower check valve element 140 may be seatedwithin the recess 174 of the lower suction cap 142. It is understoodthat a similar recess (which is not visible in the figures) may also belocated along a lower surface 180 of the upper suction cap 146 as well,and includes a profile that generally corresponds with the upper checkvalve element 134.

Referring specifically to FIG. 4, when pressure located in the uppersuction port 72 of the pneumatically actuated vacuum pump 50 is equal toor less than pressure in the Venturi gaps 102A, 102B, 102D the uppercheck valve element 134 may be seated flush within the upper suction cap146, and the tabs 166A, 166B, 166C, 166D are not bent. Similarly, whenpressure located in the lower suction port 72 of the pneumaticallyactuated vacuum pump 50 is equal to or less than pressure in the Venturigaps 102A, 102B, 102C, 102D the lower check valve element 140 may beseated flush within the lower suction cap 142, and the tabs 170A, 170B,170C, 170D are not bent. When the check valves 134, 140 are in theclosed position, air from the upper and lower suction ports 72 of thepneumatically actuated vacuum pump 50 may not be suctioned into theVenturi gaps 10A, 102B, 102C, 102D.

When the pressure located in the upper suction port 72 of thepneumatically actuated vacuum pump 50 is greater than the pressure inthe Venturi gaps 102A, 102B, 102C, 102D the upper check valve element134 may open. Specifically, the upper check valve 134 is flexible enoughsuch that the tabs 166A, 166B, 166C, 166D may bend inwardly along thefirst portion 160 and towards the Venturi gaps 102A, 102B, 102C, 102Dthereby allowing air from the upper suction port 72 to be suctioned intothe Venturi gaps 102A, 102B, 102C, 102D. Similarly, when the pressurelocated in the lower suction port 72 of the pneumatically actuatedvacuum pump 50 is greater than the pressure in the Venturi gaps 102A,102B, 102C, 102D the lower check valve element 140 may open.Specifically, the lower check valve 140 is flexible enough such that thetabs 170A, 170B, 170C, 170D may bend inwardly along the first portion162 and towards the Venturi gaps 102A, 102B, 102C, 102D thereby allowingair from the lower suction port 72 to be suctioned into the Venturi gaps102A, 102B, 102C, 102D.

Those skilled in the art will readily appreciate that each of the tabs166A, 166B, 166C, 166D of the upper check valve element 134 may bendindependently of one another. Similarly, each of the tabs 170A, 170B,170C, 170D of the lower check valve element 140 may also bendindependently of one another. Thus, during operation of thepneumatically actuated vacuum pump 50, only a portion of the Venturigaps 102A, 102B, 102C, 102D may have their corresponding check valvesopen in order to allow air to be sucked out of the vacuum canister 30(FIG. 1), while the remaining Venturi gaps 102A, 102B, 102C, 102D mayhave their corresponding check valves closed. Those skilled in the artwill readily appreciate that the check valves 134, 140 illustrated inthe figures are one embodiment of the present disclosure, and that othertypes of check valves may be used as well.

FIG. 6 is an enlarged, cross sectioned view of the Venturi gaps 102A,102B, 102C, 102D located within the housing 110 of the pneumaticallyactuated vacuum pump 50. As described above, the Venturi gap 102A may bedefined as the lineal distance L1 measured between the outlet end 96 ofthe first tapering portion 92 (seen in FIG. 5) and the inlet end 98 ofthe second tapering portion 93 (seen in FIG. 5). The remaining Venturigaps 102B, 102C, 102D also include respective lineal distances L2, L3,L4. These lineal distances are each measured from a respective inletwall and an outlet wall of each gap. Specifically, Venturi gap 102B ismeasured between an inlet surface 182 and an outlet surface 184, Venturigap 102C is measured between an inlet surface 186 and an outlet surface188, and Venturi gap 102D is measured between an inlet surface 190 andan outlet surface 192. The inlet surfaces 182, 186, and 190 and theoutlet surfaces 184, 188, and 192 are all defined by the housing 110 ofthe pneumatically actuated vacuum pump 50.

FIG. 7 is an illustration of the pneumatically actuated vacuum pump 50when viewed from the discharge port 74. Referring to FIGS. 6, and 7, thediverging profile of the second tapering portion 93 of the pneumaticallyactuated vacuum pump 50 creates an offset or difference in the inlet andoutlet openings of each Venturi gap 102A, 102B, 102C, and 102D. As seenin FIGS. 5, 7, 8 and 9, the inlet and outlet openings of the Venturigaps 102A, 102B, 102C, 102D each include a substantially ellipticalprofile. However, as explained above, in another embodiment the inletand outlet openings may include another type of profile instead. Aslabeled in FIG. 7, but as applicable to FIGS. 5, 8, and 9 also, theoutlet end 96 of the first tapering portion 92 (which represents theinlet of the Venturi gap 102A) includes an opening O1, and the inlet end98 of the second tapering portion 93 (which represents the outlet of theVenturi gap 102A) includes an opening O2. The profile of the opening O2of the outlet is sized to be greater than the opening O1 of the inlet ofthe Venturi gap 102A. In other words, there is an offset between theinlet and the outlet openings of the Venturi gap 102A. A first offset 1represents the difference between the inlet and outlet openings of theVenturi gap 102A. In one non-limiting embodiment, the first offset 1 maybe about 0.25 millimeters.

Continuing to refer to both FIGS. 6 and 7, an opening O3 is associatedwith the inlet surface 182 of the Venturi gap 102B, and an opening O4 isassociated with the outlet surface 184 of the second gap 102B. Similarto the Venturi gap 102A, the opening O4 of the outlet surface 184 isgreater than the opening O3 of the inlet surface 182. A second offset 2represents the difference between the inlet surface 182 and the outletsurface 184 of the second gap 102B. Similarly, an opening O5 isassociated with the inlet surface 186 of the Venturi gap 102C, and anopening O6 is associated with the outlet 188 of the Venturi gap 102C. Athird offset 3 represents the difference between the inlet surface 186and the outlet surface 188 of the Venturi gap 102C. Finally, an openingO7 is associated with the inlet surface 190 of the Venturi gap 102D, andan opening O8 is associated with the outlet 192 of the Venturi gap 102D.A fourth offset 4 represents the difference between the inlet surface190 and the outlet surface 192 of the Venturi gap 102D.

Referring generally to FIGS. 5 and 6, during operation an area ofminimum pressure may be created within the body 78 of the pneumaticallyactuated vacuum pump 50. In particular, the area of minimum pressure maybe located adjacent or within one or more of the Venturi gaps 102A,102B, 102C, 102D of the pneumatically actuated vacuum pump 50. The areaof minimum pressure also represents an area of maximum velocity withinthe pneumatically actuated vacuum pump 50. Those skilled in the art willreadily appreciate that if the pneumatically actuated vacuum pump 50 isoperating as an ejector, then as the motive pressure of thepneumatically actuated vacuum pump 50 increases the location of theminimum pressure within the pneumatically actuated vacuum pump 50 mayshift or move downstream within the second tapering portion 73. As thelocation of minimum pressure within the pneumatically actuated vacuumpump 50 shifts downstream of the Venturi gap 102A, the Venturi gaps102B, 102C, 102D may be used to further suction air out of the vacuumcanister 30. Those skilled in the art will also readily understand thatif the pneumatically actuated vacuum pump 50 is operating as anaspirator, then as the pressure at the discharge port 74 decreases thelocation of the minimum pressure may also shift or move downstream aswell.

Continuing to refer to FIG. 6, the lineal distances L1, L2, L3, L4 ofeach of the Venturi gaps 102A, 102B, 102C, 102D located within thehousing 110 of the pneumatically actuated vacuum pump 50 may be adjustedor tuned in order to accommodate the location of the minimum pressurewithin the pneumatically actuated vacuum pump 50. Specifically, one ofthe lineal distances L1, L2, L3, L4 of one of the Venturi gaps 102A,102B, 102C, 102D located within the housing 110 of the pneumaticallyactuated vacuum pump 50 may be designed to be narrower or decreased inlength if a higher suction vacuum (i.e., lower suction pressures) at aspecific set of operating conditions is desired.

In addition to decreasing the length of one of the Venturi gaps 102A,102B, 102C, 102D, the offset distances (i.e., the first offset 1, thesecond offset 2, the third offset 3, or the fourth offset 4) may bedecreased as well in order to produce a higher suction vacuum (i.e.,lower suction pressures) at a specific set of operating conditions. Inother words, if a specific one of the Venturi gaps decreases in length,then the difference between the respective inlet and outlet opening ofthe specific gap should also decrease as well. Similarly, one of thelineal distances L1, L2, L3, L4 of one of the Venturi gaps 102A, 102B,102C, 102D located within the housing 110 of the pneumatically actuatedvacuum pump 50 may be designed to be wider or increased in length if ahigher suction flow rate at a specific set of operating conditions isdesired. In addition to increasing the length of one of the Venturi gaps102A, 102B, 102C, 102D, the offset distance associated with one of theVenturi gaps (i.e., the first offset 1, the second offset 2, the thirdoffset 3, or the fourth offset 4) should be increased as well in orderto produce a higher suction flow rate at a specific set of operatingconditions. In other words, if a specific one of the Venturi gapsincreases in length, then the difference between the respective inletand outlet openings of the specific gap should also increase as well.

A specific set of operating conditions may be defined by the pressuresat both the motive port 70 as well as the discharge port 74 of thepneumatically actuated vacuum pump 50. For example, during one set ofoperating conditions the motive port 70 is at atmospheric pressure andif the discharge port 74 is at about eighty percent of atmosphericpressure. During this set of operating conditions, the pneumaticallyactuated vacuum pump 50 is operating as an aspirator. In this example,the location of the minimum pressure within the pneumatically actuatedvacuum pump 50 may be assumed or determined to be at the Venturi gap102A. If the engine 12 (seen in FIG. 1) operates to produce theseexemplary conditions for a significant amount of time, then a designeror engineer may determine it generally advantageous to adjust the linealdistance L1 of the Venturi gap 102A accordingly (i.e., the linealdistance L1 of the Venturi gap 102A should be widened or narroweddepending on requirements). In addition to adjusting the lineal distanceL1, it is to be understood that the second offset 2 may also be adjustedaccordingly as well. For example, if the lineal distance L1 of theVenturi gap 102A is increased, then the second offset 2 may increase aswell. Similarly, if the lineal distance L1 of the Venturi gap 102A isdecreased, then the second offset 2 may decrease as well.

In another illustrative example, if the pressure of the motive port 70is higher than atmospheric pressure (e.g., at about 168 kilopascals) andif the discharge port 74 is also higher than atmospheric pressure butless than the motive port 70 (e.g., at about 135 kilopascals), then thepneumatically actuated vacuum pump 50 is operating as an ejector. Inthis example, the location of the minimum pressure within thepneumatically actuated vacuum pump 50 is assumed or determined to be atthe Venturi gap 102C. If the engine 12 (seen in FIG. 1) operates toproduce these exemplary conditions for a significant amount of time,then a designer or engineer may determine it generally advantageous toadjust the lineal distance L3 of the Venturi gap 102C accordingly (i.e.,either the Venturi gap 102C should be widened or narrowed). In additionto adjusting the lineal distance L3 of the Venturi gap 102C, it is to beunderstood that the third offset 3 may also be adjusted accordingly aswell. For example, if the lineal distance L3 of the Venturi gap 102C isincreased, then the third offset 3 may increase as well. Similarly, ifthe lineal distance L3 of the Venturi gap 102C is decreased, then thethird offset 3 may decrease as well.

Referring now to FIGS. 8 and 9, two alternate embodiments are providedin which the first and second Venturi gaps 102A and 102B are in fluidcommunication with a first suction port 72′a, 72′c, respectively, andthe second and third Venturi gaps 102C and 102D are in fluidcommunication with the second suction port 72′b, 72′d, respectively. Thefluid communication is controlled by the presence of a check valveelement 134 and/or 140, if present. The first suction ports 72′a, 72′care connected to a first device requiring vacuum 32 a and the secondsuction ports 72′b, 72′d are connected to a second device requiringvacuum 32 b.

In this first dedicated suction port embodiment, the first devicerequiring vacuum 32 a is a brake boost canister and the second devicerequiring vacuum 32 b is a fuel vapor purge canister. For this firstembodiment, as shown in both FIGS. 8 and 9, the first and second Venturigaps 102A and 102B are positioned closer to the motive exit. Thisposition of the Venturi gaps is advantageous for higher vacuum suction,which is desirable for a brake boost system, compared to those Venturigaps closer to the outlet end 100 of the discharge section 95. Moreover,as explained above, the first and second Venturi gaps 102A and 102B canbe tuned for higher vacuum suction by decreasing the lineal distance L1and/or decreasing the first offset 1 and/or the second offset 2. In thisfirst embodiment, the third and fourth Venturi gaps 102C and 102D arepositioned closer to the outlet end 100 of the discharge section 95.This position of the Venturi gaps is advantageous for higher suctionflow rate, typically for a longer time, which is desirable for a fuelvapor purge canister, compared to the first and second Venturi gaps 102Aand 102B. Moreover, as explained above, the third and fourth Venturigaps 102C and 102D can be tuned for higher suction flow rates byincreasing the lineal distance L3 and/or L4 and/or increasing the thirdoffset 3 and/or the fourth offset 4.

In another dedicated suction port embodiment, the first device requiringvacuum 32 a is a turbocharger bypass pneumatic actuator and the seconddevice requiring vacuum 32 b is a fuel vapor purge canister. Here, asshown in both FIGS. 8 and 9, the first and second Venturi gaps 102A and102B are connected to the first device requiring vacuum and arepositioned closer to the motive exit. This position of the Venturi gapsis advantageous for higher vacuum suction, which is desirable for aturbocharger bypass pneumatic actuator. Moreover, as explained above,the first and second Venturi gaps 102A and 102B can be tuned for highervacuum suction by decreasing the lineal distance L1 and/or decreasingthe first offset 1 and/or the second offset 2. Moreover, if additionalvacuum is needed to operate the turbocharger bypass pneumatic actuator,the third Venturi gap 102C may also be in fluid communication with onlythe first suction port 72′a, 72′c. Accordingly, the third and fourthVenturi gaps 102C and 102D or the fourth Venturi gap 102D alone, or thefourth Venturi gap 102D and one or more additional Venturi gaps (notshown) may be in fluid communication with the second device requiringvacuum 32 b. This position of the Venturi gaps, which is closer to theoutlet end 100 of the discharge section 95, is advantageous for highersuction flow rate, typically for a longer time, which is desirable for afuel vapor purge canister. Moreover, as explained above, these Venturigaps can be tuned for higher suction flow rates by increasing theirrespective lineal distances and/or increasing the their respectiveoffsets 3.

It is to be understood that various combination of devices are possiblefor the first and second devices requiring vacuum 32 a, 32 b and furtherthat a third and/or fourth device requiring vacuum may be connected tothe same evacuator as well by additional suction ports, as explainedabove. Depending upon the number of devices requiring vacuum and thetype of devices, the Venturi gaps 102A, 102B, 102C, 102D connected tothe respective devices should be chosen depending upon the device's needfor high or low suction vacuum and high or low suction flow rate and thesame may be adjusted or tuned to those needs. For example, in oneembodiment, one of the Venturi gaps 102A, 102B, 102C, 102D may beincreased in length to provide a higher suction flow rate at a first setof operating conditions, and the remaining Venturi gaps 102A, 102B,102C, 102D may be decreased in length to provide a higher suction vacuumat another set of operating conditions.

Again referring to FIG. 9, the fluid communication between the Venturigaps 102A-102D is controlled by the presence of a check valve elements134, 140. Here, since only the first and second Venturi gaps 102A and102B fluidly communicate with the first suction port 72′c, anobstruction 204 is present that obstructs (prevents) fluid communicationbetween any downstream Venturi gaps and the first suction port 72′c.Similarly, since only the third and fourth Venturi gaps 102C and 102Dfluidly communication with the second suction port 72′d, an obstruction202 is present that obstructs (prevents) fluid communication between anyupstream Venturi gaps and the second suction port 72′d.

In an alternate embodiment, as provided in FIG. 10, rather than havingobstructions 202 or 204 coordinated with selected Venturi gaps, a checkvalve element 208 is provided that includes selected tabs thereof thatare rigid, those included on the right section 212, and other selectedtabs that are elastically flexible, those included on the left section210, to move between a closed position and an open position. While thecheck valve element 208 is illustrated as having one-half rigid tabs andone-half flexible tabs, the rigid and flexible tabs may be dispersed asneeded to coordinate with selected Venturi gaps and their respectivesuction ports.

Fletch insert 220, as shown in FIG. 8, may be included in any of theembodiments disclosed herein. The fletch insert 220 is described as setforth in co-pending, co-owned U.S. provisional Patent Application No.62/042,569 filed on Aug. 27, 2014, which is incorporated in its entiretyherein by reference.

Referring now to FIG. 11, an exemplary turbocharged engine air system300 for providing vacuum is disclosed. The engine air system 300 mayinclude an internal combustion engine 312, an air cleaner 314, a flowvalve 316, a multi-port evacuator 330, a compressor 324, a turbine (notshown), a throttle 328, and a fuel vapor canister 331. As explained ingreater detail below, the multi-port evacuator 330 may provide vacuum toa plurality of vacuum consuming devices such as a brake boost canister(not illustrated in FIG. 11), the fuel vapor canister 331, and acrankcase ventilation system 352.

Similar to the embodiment as shown in FIG. 1, the internal combustionengine 312 may be, for example, an SI engine, a CI engine, or part of anelectric motor/battery system in a hybrid vehicle. The compressor 324and turbine may be part of a turbocharger for improving the power outputand overall efficiency of the internal combustion engine 312. Theturbine may include a turbine wheel (not illustrated in FIG. 11) thatharnesses and converts exhaust energy into mechanical work through acommon shaft to turn a compressor wheel (not illustrated in FIG. 11) ofthe compressor 324. The compressor wheel ingests, compresses, and feedsair at elevated operating pressures into an intake manifold 342 of theinternal combustion engine 312. The throttle 328 is located downstreamof the air cleaner 314 and the compressor 324, and upstream of theintake manifold 342 of the internal combustion engine 312.

The evacuator 330 includes a first motive inlet 332, a second motiveinlet 334, a first discharge outlet 336, a second discharge outlet 338,and a pneumatically actuated vacuum pump 340. In the embodiment as shownin FIG. 11, the first motive inlet 332 of the evacuator 330 is fluidlyconnected with the fuel vapor canister 331, as represented by conduitline 342. The flow valve 316 is located within the conduit line 342. Theflow valve 316 may be a shut-off valve, and is used to control whethervacuum is provided to the fuel vapor canister 331. Those skilled in theart will readily appreciate that the fuel vapor canister 331 may onlyneed purging for a specified period of time after start-up of a vehicle.One non-limiting example of the flow valve is described in co-pending,co-owned U.S. provisional Patent Application No. 61/914,658 filed onDec. 11, 2013, which is incorporated in its entirety herein byreference.

Continuing to refer to FIG. 11, the second motive inlet 334 of theevacuator 330 is fluidly connected with the crankcase ventilation system352, as represented by conduit line 344. Both the discharge outlets 336,338 of the evacuator 330 are fluidly connected to the engine air system300 at a location upstream of the intake manifold 342 and downstream ofan outlet 329 of the throttle 328. Specifically, a first check valve 350may be included in a conduit line 348 between the first discharge outlet336 of the evacuator 330 and junction between the throttle 328 and theintake manifold 342. Similarly, a second check valve 354 may be includedin a conduit line 349 between the second discharge outlet 338 of theevacuator 330 and junction between the throttle 328 and the intakemanifold 342.

The pneumatically actuated vacuum pump 340 may supply vacuum to aplurality of vacuum consuming devices. In particular, the pneumaticallyactuated vacuum pump 340 supplies vacuum to the brake boost canister(not illustrated), the fuel vapor canister 331, and the crankcaseventilation system 352. As explained in greater detail below, thepneumatically actuated vacuum pump 340 is fluidly connected to the brakeboost canister, the fuel vapor canister 331, and the crankcaseventilation system 352 via a plurality of upper suction ports A1, B1,C1, D1. The pneumatically actuated vacuum pump 340 is also fluidlyconnected to the brake boost canister, the fuel vapor canister 331, andthe crankcase ventilation system 352 via a plurality of lower suctionports A2, B2, C2, D2. Those skilled in the art will readily appreciatethat while the brake boost canister, fuel vapor canister 331, and thecrankcase ventilation system 352 are illustrated or described in FIG.11, the pneumatically actuated vacuum pump 340 may include additionalsuction ports to provide vacuum to other vacuum consuming devices withina vehicle as well. Alternatively, the pneumatically actuated vacuum pump340 may provide vacuum to different vacuum consuming devices within avehicle instead.

The evacuator 330 may operate to produce vacuum to the various vacuumrequiring systems if the pressure at the motive inlets 332, 334 of theevacuator 330 are at atmospheric pressure and the pressure at thedischarge outlets 336, 338 are less than the pressure at the motiveinlets 332, 334. In other words, the evacuator 330 operates as anaspirator during operation of the engine 312.

As illustrated in FIG. 11, the evacuator 330 includes multiple suctionports connected to the multiple devices requiring vacuum. Specifically,the first upper suction port A1, located closest to the first motiveinlet 332 of the evacuator 330, is fluidly connected to the brakebooster system. The second upper suction port B1, which is locatedimmediately adjacent to the first suction port A1 of the evacuator 330,is fluidly connected to the brake booster system as well. As explainedabove, the proximity of the first and second upper suction ports A1, B1to the first motive inlet 332 of the evacuator 330 facilitates a highervacuum suction, which is required by brake boost systems. Similarly, thefirst lower suction port A2, located closest to the second motive inlet334 of the evacuator 330, is also fluidly connected to the brake boostersystem. The second lower suction port B2, which is located immediatelyadjacent to the suction port A2 of the evacuator 330, is fluidlyconnected to the brake booster system as well. The proximity of thelower first and second suction ports A2, B2 to the second motive inlet334 of the evacuator 330 facilitates a higher vacuum suction as well.

Continuing to refer to FIG. 11, the third upper suction port C1, whichis immediately adjacent to second upper suction port B1 of the evacuator330, is fluidly connected to the fuel vapor canister 331. The fourthupper suction port D1, which is immediately adjacent the first dischargeoutlet 336 of the evacuator 330, is fluidly connected to the crankcaseventilation system 352. As explained above, the proximity of the upperthird and fourth suction ports C1, D1 to the discharge outlet 336 of theevacuator 330 facilitates a higher suction flow rate. Similarly, thethird lower suction port C2, which is immediately adjacent to secondlower suction port B2 of the evacuator 330, is also fluidly connected tothe fuel vapor canister 331. The fourth lower suction port D2, which isimmediately adjacent the second discharge outlet 338 of the evacuator330, is fluidly connected to the crankcase ventilation system 352. Theproximity of the third and fourth lower suction ports C2, D2 to thesecond discharge outlet 338 of the evacuator 330 facilitates a highersuction flow rate as well.

FIG. 12 is an elevated view of the pneumatically actuated vacuum pump340, and FIG. 13 is a cross-sectioned view of the pneumatically actuatedvacuum pump 340 taken along section line C-C in FIG. 12. Referring toboth FIGS. 12 and 13, the pneumatically actuated vacuum pump 340 maydefine two passageways 480, 482. Specifically, a first or upperpassageway 480 may define the first motive inlet 332 and the firstdischarge outlet 336. The upper passageway 480 may include a firsttapering portion 492 (also referred to as a motive cone) in a motivesection 490 of the upper passageway 480. The upper passageway 480 mayalso include a second tapering portion 493 (also referred to as adischarge cone) in a discharge section 495 of the upper passageway 480.The first tapering portion 492 of the passageway 480 may include aninlet end 494 and an outlet end 496. Similarly, the second taperingportion 493 of the upper passageway 480 may also include an inlet end498 and an outlet end 500.

A second or lower passageway 482 may define the second motive inlet 334and the second discharge outlet 338. The lower passageway 482 mayinclude a first tapering portion 492′ in a motive section 490′ of thelower passageway 482. The lower passageway 482 may also include a secondtapering portion 493′ in a discharge section 495′ of the lowerpassageway 482. The first tapering portion 492′ of the lower passageway482 may include an inlet end 494′ and an outlet end 496′. Similarly, thesecond tapering portion 493′ of the lower passageway 482 may alsoinclude an inlet end 498′ and an outlet end 500′. It is to be understoodthat while the figures illustrate the evacuator 330 including two motiveinlets and two motive outlets, the evacuator 330 may include more thantwo motive inlets as well. Furthermore, the evacuator 330 may alsoinclude more than two discharge outlets as well. However, it is to beunderstood that the number of motive inlets of the evacuator 330 shouldbe equal to the number of discharge outlets.

As seen in FIG. 13, the first tapering portions 492, 492′ of thepneumatically actuated vacuum pump 340 may be fluidly coupled to thesecond tapering portions 493, 493′ by a Venturi gap 502A. In particular,the Venturi gap 502A may be located between the outlet ends outlet end496, 496′ of the first tapering portions 492, 492′ and the inlet ends498, 498′ of the second tapering portions 493, 493′. A body 508 of thepneumatically actuated vacuum pump 340 may define a housing 510. Thehousing 510 may surround or define a portion of the second taperingportions 593, 593′ of the pneumatically actuated vacuum pump 340. Inparticular, the housing 508 may define the Venturi gap 502A, as well asa plurality of additional gaps 502B, 502C, 502D. In the embodiment asillustrated, the housing 510 may include a generally rectangularprofile, however it is understood that the embodiment is merelyexemplary in nature and the housing 510 is not limited to a rectangularprofile.

The Venturi gaps 502B, 502C, 502D are located downstream of Venturi gap502A, within the housing 508. In the embodiments shown in the figures,the pneumatically actuated vacuum pump 340 includes a total of fourVenturi gaps. It is to be understood that these illustrations are merelyexemplary embodiments of the pneumatically actuated vacuum pump 340 andthat any number of Venturi gaps are possible. In particular, in anotherembodiment the evacuator 330 may only include a single Venturi gap usedto fluidly couple the first tapering portions 492, 492′ of thepneumatically actuated vacuum pump 340 to the second tapering portions493, 493′. However, those skilled in the art will readily appreciatethat in the embodiment as shown in FIG. 11, at least four Venturi gapsare required so that at least Venturi gaps 502A, 502B may be in fluidcommunication with the brake boost canister, the Venturi gap 502C may bein fluid communication with fuel vapor canister 331 (FIG. 11), and theVenturi gap 502D may be in fluid communication with the crankcaseventilation system 352 (FIG. 11).

As seen in FIG. 13, a fletch insert 516 may be disposed within the firsttapering portion 492 of the evacuator 330, and may extend into one ormore of the Venturi gaps 502A, 502B, 502C, 502D. Similarly, a fletchinsert 516′ may be disposed within the first tapering portion 492′ ofthe evacuator 330 as well, and may also extend into one or more of theVenturi gaps 502A, 502B, 502C, 502D.

Each Venturi gap 502A, 502B, 502C, 502D may be a void located within thehousing 508. Specifically, Venturi gaps 502A, 502B, 502C, 502D may eachbe similar to an interior cross-section of the housing 508. For example,the Venturi gap 102A may include a generally rectangular profile thatsubstantially corresponds with the interior cross-section of the housing508. In particular, the first upper suction port A1 may correspond withVenturi gap 502A of the evacuator 330, the second upper suction port B1may correspond with Venturi gap 502B of the evacuator 330, the thirdupper suction port C1 may correspond with Venturi gap 502C of theevacuator 330, and finally the fourth upper suction port D1 maycorrespond with Venturi gap 502D of the evacuator 330. Similarly, thefirst lower suction port A2 may correspond with Venturi gap 502A of theevacuator 330, the second lower suction port B2 may correspond withVenturi gap 502B of the evacuator 330, the third lower suction port C2may correspond with Venturi gap 502C of the evacuator 330, and finallythe fourth lower suction port D2 may correspond with Venturi gap 502D ofthe evacuator 330. Although the lower suction ports A2, B2, C2, D2 arenot visible in FIGS. 12-13, it is to be understood that the housing 510includes an upper surface 512 (seen in FIG. 12) and a lower surface 514.The lower surface 514 (which is not fully visible in the figures) issubstantially identical in shape and geometry as the upper surface 512of the housing 510.

Referring to FIGS. 11-13, the Venturi gaps 502A and 502B draw in airfrom the first and second upper suction ports A1, B1 as well as thefirst and second lower suction ports A2, B2 all at the same time. TheVenturi gap 502C is used to draw in air from the third upper suctionport C1 as well as the third lower suction port C2. Finally, the Venturigap 502D is used to draw in air from the fourth upper suction port D1 aswell as the fourth lower suction port D2. Similar to the embodiments asdiscussed above and illustrated in FIGS. 2-10, the Venturi gaps 502A,502B, 502C, 502D may be tuned or adjusted based on the number of devicesrequiring vacuum, as well as the specific type of devices requiringvacuum. For example, in one embodiment, the Venturi gaps 502A, 502B maybe increased in length to provide a higher suction vacuum at a first setof operating conditions, and the remaining Venturi gaps 502C, 502D maybe decreased in length to provide a higher suction flow rate at anotherset of operating conditions.

Continuing to refer to FIGS. 11-13, the fluid communication between theVenturi gaps 502A-502D and the various devices requiring vacuum may becontrolled by the presence of check valve elements (not illustrated inFIGS. 12-13). Specifically, a check valve element, similar to the checkvalve element 134 shown in FIG. 4, may be disposed along the uppersurface 512 of the housing 510 of the evacuator 330. However, it is tobe understood that the check valve element disposed along the uppersurface 512 of the housing 510 should be shaped to correspond with thespecific geometry of the Venturi gaps 502A-502D. Similarly, a checkvalve element, similar to the check valve element 140 shown in FIG. 4,may be disposed along the lower surface 514 of the housing 510 of theevacuator 330. The check valve element disposed along the lower surface514 of the housing 510 should be shaped correspond with the specificgeometry of the Venturi gaps 502A-502D.

In the embodiment as illustrated in FIGS. 12-13, the Venturi gaps 502A,502B, 502C, 502D are each in fluid communication with the first motiveinlet 332, the second motive inlet 334, the first discharge outlet 336,and the second discharge outlet 338. In other words, the evacuator 330operates as a single, unitary evacuator device. Turning now to FIG. 14,an alternative embodiment of an evacuator 330′ for providing vacuum isdisclosed. The evacuator 330′ includes all the components of theevacuator 330 shown in FIGS. 12-13 and as such like reference numberrefer to the same components and a description thereof is not duplicatedhere. However, unlike the embodiment as shown in FIGS. 11-12, theevacuator 330′ includes a partitioning wall 320′ located within thehousing 510, and extending in a direction that is substantially parallelwith the motive inlets 32, 334 and the discharge outlets 336, 338. Inother words, the partitioning wall 320′ extends in a directionsubstantially parallel with the flow of fluid within the evacuator 330.

The partitioning wall 320′ may be used to section off or isolateportions of the Venturi gaps such that fluid may only flow from one ofthe motive inlets 332, 334 to a respective one of the discharge outlets336, 338. Specifically, as seen in FIG. 14, the partitioning wall 320′creates a plurality of first Venturi gaps 502A′, 502B′, 502C′, 502D′ aswell as a plurality of second Venturi gaps 502A″, 502B″, 502C″, 502D″.Each of the first Venturi gaps 502A′, 502B′, 502C′, 502D′ are fluidlyconnected to the first motive inlet 332 and the first discharge outlet336. Thus, fluid passing through the first motive inlet 332 may onlyexit though the first discharge outlet 336 of the evacuator 330′.Similarly, each of the second Venturi gaps 502A″, 502B″, 502C″, 502D″are fluidly connected to the second motive inlet 334 and the seconddischarge outlet 338.

It is appreciated that the partitioning wall 320′ enables the evacuator330′ to operate as two distinct evacuators within the same component. Inother words, the first motive inlet 332, the first discharge outlet 336,and the first Venturi gaps 502A′, 502B′, 502C′, 502D′ cooperate togetherto operate as a first evacuator, and the second motive inlet 334, thesecond discharge outlet 338, and the second Venturi gaps 502A″, 502B″,502C″ also cooperate together to operate as a second evacuator. Thoseskilled in the art will readily appreciate that the disclosed evacuator330′ may be molded as a single, unitary part, thereby reducing the costand complexity associated with molding two separate components.

Although a turbocharged engine air system 300 is disclosed in FIG. 11,it is to be understood that any of the disclosed evacuators 330, 330′may also be used in a non-boosted engine as well. FIG. 15 is anillustration of a normally aspirated engine air system 600. The engineair system 300 may include an internal combustion engine 612, an aircleaner 614, a flow valve 616, the evacuator 330, a throttle 628, and afuel vapor canister 631. Similar to the embodiment as shown in FIG. 11,the evacuator 330 may provide vacuum to a plurality of vacuum consumingdevices such as a brake boost canister (not illustrated in FIG. 15), thefuel vapor canister 631, and a crankcase ventilation system 652.

The internal combustion engine 612 may be, for example, an SI engine, aCI engine, or part of an electric motor/battery system in a hybridvehicle. However, it is appreciated that unlike the embodiment as shownin FIG. 11, the internal combustion engine 612 is normally aspirated andnot boosted (i.e., no turbo charger is included). The throttle 628 islocated downstream of the air cleaner 614 and upstream of an intakemanifold 642 of the internal combustion engine 612.

In the embodiment as shown in FIG. 15, the first motive inlet 332 of theevacuator 330 is fluidly connected with the fuel vapor canister 331, asrepresented by conduit line 642. The flow valve 616 is located withinthe conduit line 642. The second motive inlet 334 of the evacuator 330is fluidly connected with the crankcase ventilation system 652, asrepresented by conduit line 644. Both the discharge outlets 336, 338 ofthe evacuator 330 are fluidly connected to the engine air system 600 ata location upstream of the intake manifold 642 and downstream of anoutlet 629 of the throttle 628. A conduit line 648 may fluidly connectthe first discharge outlet 336 of the of the evacuator 330 with ajunction between the throttle 628 and the intake manifold 642.Similarly, a conduit line 649 may fluidly connect the second dischargeoutlet 338 of the of the evacuator 330 and a junction between thethrottle 628 and the intake manifold 642.

Referring generally to FIGS. 11-15, the disclosed engine air systemsprovide a relatively simple, cost-effective approach for supplyingvacuum to various devices within a vehicle. In particular, the disclosedevacuators may be used to provide a low-cost approach for providingeither high suction vacuum or high suction flow rate to multiple vacuumconsuming devices within a vehicle. Moreover, it is to be appreciatedthat the motive inlets of the disclosed evacuator may be fluidlyconnected to both the crankcase ventilation system and the fuel vaporcanister. Thus, the engine air consumed by the crankcase ventilationsystem and the fuel vapor canister may be used to generate vacuum thatis used by those very same systems themselves.

The embodiments of this invention shown in the drawings and describedabove are exemplary of numerous embodiments that may be made within thescope of the appended claims. It is contemplated that numerous otherconfigurations of the disclosure may be created taking advantage of thedisclosed approach. In short, it is the applicant's intention that thescope of the patent issuing herefrom will be limited only by the scopeof the appended claims.

What is claimed is:
 1. A pneumatically actuated vacuum pump forproviding vacuum, comprising: a body defining: at least two convergingmotive sections each having an outlet end; at least two divergingdischarge sections each having an inlet end; at least one Venturi gaplocated between the outlet ends of the at least two converging motivesections and the inlet ends of the at least two diverging dischargesections; a first passageway defined by one of the at least twoconverging motive sections, one of the at least two diverging dischargesections, and the Venturi gap, wherein the Venturi gap fluidly couplesthe one of the at least two converging motive sections and the one ofthe at least two diverging discharge sections together; and a secondpassageway defined by a remaining one of the at least two convergingmotive sections and a remaining one of the at least two divergingdischarge sections and the Venturi gap, wherein the Venturi gap fluidlycouples the remaining one of the at least two converging motive sectionsand the remaining one of the at least two diverging discharge sectionstogether.
 2. The pneumatically actuated vacuum pump of claim 1, furthercomprising at least one additional gap located downstream of the Venturigap.
 3. The pneumatically actuated vacuum pump of claim 1, wherein thebody defines a housing that surrounds a portion of the at least twodiverging discharge sections and contains the Venturi gap.
 4. Thepneumatically actuated vacuum pump of claim 3, further comprising apartitioning wall located within the housing.
 5. The pneumaticallyactuated vacuum pump of claim 4, wherein the partitioning wall extendsin a direction substantially parallel with the at least two motiveinlets and the at least two discharge outlets.
 6. The pneumaticallyactuated vacuum pump of claim 4, wherein the partitioning wall isolatesa portion of the Venturi gap such that fluid may only flow from each ofthe at least two motive inlets to a respective one of the at least twodischarge outlets.
 7. The pneumatically actuated vacuum pump of claim 1,wherein three additional gaps are located downstream of the Venturi gap.8. The pneumatically actuated vacuum pump of claim 7, wherein theVenturi gap and a selected one of the additional gaps locatedimmediately adjacent to the Venturi gap are shaped to generate a highersuction vacuum than a remaining two additional gaps.
 9. Thepneumatically actuated vacuum pump of claim 8, wherein the remaining twoadditional gaps are shaped to generate a higher suction flow rate thanthe Venturi gap and the selected one of the three additional gapslocated immediately adjacent to the Venturi gap.
 10. A turbochargedengine air system, comprising: at least two devices requiring vacuum; aturbocharger having a compressor fluidly connected to an intake manifoldof an engine; and a pneumatically actuated vacuum pump of claim 1defining at least two Venturi gaps located between each of the outletends of the at least two converging motive sections and the inlet endsof the at least two diverging discharge sections, and at least twosuction ports in fluid communication, one each, with one of the at leasttwo Venturi gaps; wherein the at least two discharge sections arefluidly connected to the intake manifold of the engine at a locationdownstream of the compressor, and wherein each of the at least twosuction ports are fluidly connected to one of the at least two devicesrequiring vacuum.
 11. The system of claim 10, wherein the at least twodevices include a fuel vapor canister, a crankcase ventilation system,and a brake boost canister.
 12. The system of claim 11, wherein one ofthe at least two motive sections of the evacuator is fluidly connectedto the fuel vapor canister.
 13. The system of claim 11, wherein one ofthe at least two motive sections of the evacuator is fluidly connectedto the crankcase ventilation system.
 14. The system of claim 11, whereinthe evacuator includes four suction ports, and wherein a first suctionport and a second suction port of the evacuator are both fluidlyconnected to the brake booster, a third suction port of the evacuator isfluidly connected to the fuel vapor canister, and a fourth suction portof the evacuator is fluidly connected to the crankcase ventilationsystem.
 15. The system of claim 10, wherein the one of the at least twomotive sections of the evacuator is fluidly connected to one of the atleast two devices, and another of the at least two motive sections isfluidly connected to a remaining one of the at least two devices.
 16. Anormally aspirated engine air system including an engine and a throttlelocated upstream of an intake manifold of the engine, comprising: atleast two devices requiring vacuum; and a pneumatically actuated vacuumpump of claim 1 defining at least two Venturi gaps located between eachof the outlet ends of the at least two converging motive sections andthe inlet ends of the at least two diverging discharge sections, and atleast two suction ports in fluid communication, one each, with one ofthe at least two Venturi gaps; wherein the at least two dischargesections are fluidly connected to the intake manifold of the engine at alocation downstream of the throttle, and wherein each of the at leasttwo suction ports are fluidly connected to one of the at least twodevices requiring vacuum.
 17. The system of claim 16, wherein the atleast two devices include a fuel vapor canister, a crankcase ventilationsystem, and a brake boost canister.
 18. The system of claim 17, whereinone of the at least two motive sections of the evacuator is fluidlyconnected to the fuel vapor canister.
 19. The system of claim 17,wherein one of the at least two motive sections of the evacuator isfluidly connected to the crankcase ventilation system.
 20. The system ofclaim 17, wherein the evacuator includes four suction ports, and whereina first suction port and a second suction port of the evacuator are bothfluidly connected to the brake booster, a third suction port of theevacuator is fluidly connected to the fuel vapor canister, and a fourthsuction port of the evacuator is fluidly connected to the crankcaseventilation system.
 21. The system of claim 16, wherein the one of theat least two motive sections of the evacuator is fluidly connected toone of the at least two devices, and another of the at least two motivesections is fluidly connected to a remaining one of the at least twodevices.